Before you scoff at the idea of Kia's all-new $66,000 K900 full-size sedan, remember Lexus.

Twenty-five years ago, it was absurd to think that a Japanese brand could build a high-end vehicle to challenge German luxury car leaders Mercedes, BMW and Audi.

Then Toyota's Lexus brand came out with the LS.

Like the Germans, the LS packed a V-8 and rear-wheel drive into a full-size sedan. But it did so for mid-size, V-6 money.

Critics and customers loved it. Two years later, Lexus was the bestselling premium brand in the U.S.

Auto review: K900 shows Kia can offer value with $66,000 price tag

Kia

The K900’s interior is more spacious than the Lexus LS 460’s.

The K900’s interior is more spacious than the Lexus LS 460’s. (Kia)

Kia Motors Corp., hoping to make similar waves in this rarefied world, began its move into the luxury market last year with the large Cadenza sedan, which topped out around $42,000.

But the South Korean automaker wanted something even fancier — a halo car that would help buyers of its cheapo Rio or Soul compact cars feel good about the brand.

Enter the K900, whose creamy smooth drivetrain, unbeatable value and legitimately luxurious construction should do all that — and maybe put a dent in sales of the Lexus LS 460.

A 5.0-liter V-8 version of the K900 went on sale in March, and it's impressive. Rated at 420 horsepower and 376 pound-feet of torque, the direct-injected engine and eight-speed automatic gearbox perform admirably.

The engine provides ample whisper-quiet power, and the transmission shifts without effort or drama — though it's a little slow on the downshift. (Switching to "sport" mode eliminates this.)

It is a little thirsty. Though the Environmental Protection Agency rates the V-8 K900 at 15 miles per gallon in the city and 23 mpg on the highway, a week of city gave us an average of 14 mpg.

On the road, our V-8 tester ate up the miles with a detached plushness. Kia has stressed comfort over handling, but the K900 offers better road feel than the completely numb Hyundai Equus on which it's based.

True, a comparably outfitted Mercedes-Benz, Audi, or BMW of equal size will deliver both comfort and responsiveness. But their V-8 models also cost at least $20,000 more.

Wrapped around all this is a body that's as unique as it could be without upsetting traditionally conservative buyers of full-size luxury sedans, with LED lights, a chromed, chain-mail grille and a rear end that looks a little like the BMW 7-Series.

The K900's interior is more spacious than the Lexus LS 460's — though it does lose some trunk space — and is also cushy. The rear passenger area is cavernous, with headrests so soft and plush they deserve their own section at Bed Bath & Beyond.

The K900's dashboard — which could use more panache if it's going to compete in the high-end market — features the same crisp and informative navigation screen we've come to love on other Kias.

(Later this year, Kia will release the K900 with a 311-horsepower V-6, at around $50,000.)

Our tester also had a $6,000 VIP package that included adaptive cruise control, a fully digital 12.3-inch instrument panel, heads-up display, power reclining rear seats that are also ventilated and a bird's-eye camera system.

Does the K900 constitute a real challenge to the Equus? Yes. It's a better car in every way.

It can also compete with the Lexus. Though the LS 460 trumps the K900 in interior design and execution, and comes from a brand with a proven track record in the luxury world, a model equivalent to this Kia would cost around $13,000 more.

So, maybe it's really Toyota Motor Corp. that should be nervous, because it can be dangerous to let your guard down in the cutthroat world of luxury. Just ask the Germans.

For America's rich and famous, the Lincoln Continental once was the last word in automotive luxury. From the 1940s through the Cold War, the elegant sedan was a staple at Hollywood premieres and presidential motorcades.